1. Field of the Invention
The present invention relates to insulated wire fabrication, and more particularly to a wire drying system which employs a water separator to separate water from air to prevent water from entering a vacuum pump.
2. Description of the Related Art
Insulated wires may include one or more layers of insulation over a cable core, a stranded or solid conductor core or a fiber optic core. Insulated wires are manufactured by drawing the core through an extruder which includes a plastic melt at high pressure and temperature. The extruder provides an insulation coating on the core which adheres to the core and has a substantially uniform thickness around the core. Plastics such as polyvinyl chloride, polyethylene or equivalent plastics are employed as insulation.
As the wire or cable is drawn from the extruder, the plastic insulation begins to cool. However, this plastic insulation is often still at the high temperature of the extruder plastic. Since plastic is a good thermal insulator, it takes a long time to cool to room temperature in air. The cable or wire is typically drawn through the extruder at a rate of about 1100 feet per minute. It is preferable to spool the wire or cable as soon as possible to maintain the manufacture rate. Therefore, in-line cooling techniques are employed.
The most commonly employed techniques includes passing the wire or cable through a cool water bath to increase heat transfer from the insulation material. One drawback of this technique is the need to dry off the wire or cable prior to spooling the wire or cable. This is typically performed by spraying high pressure air on the cable to blow the water off. Spraying the cable or wire with air jets is often noisy since the jets include spray nozzles which can cause noise levels as high as 90 decibels, and require hearing protection from operating personnel.
Another technique includes vacuuming the wire or cable to suck the water away from the wire or cable. This technique causes the cable or wire to be sucked down into a trough where the vacuum suction causes wear due to friction on the cable as well as wear of the metallic surfaces of the trough. Further, since the vacuum is sucking away the water, the vacuum pumps of conventional system often take in water which seriously compromises the pump life.
Therefore, a need exists for a water drying apparatus which avoids excessive wear on the cable and a vacuum trough employed to draw away water on the cable. A further need exists for a water separator which prevents water intake to the vacuum pump during operations.